CIG   05423
CENTRO DE INVESTIGACIONES GEOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
Caracterización química de granitoides chánicos y gondwánicos del noroeste de Patagonia.
Autor/es:
VARELA, RICARDO; GREGORI, DANIEL; GONZÁLEZ, PABLO D.; BASEI, MIGUEL
Revista:
REVISTA GEOLóGICA DE CHILE
Referencias:
Lugar: Santiago; Año: 2008
ISSN:
0716-0208
Resumen:
On the basis of 23 whole rock chemical analysis of the crystalline basement from the Northwest Patagonia, Neuquén, Río Negro and Chubut provinces, we characterize the magmatism and tectonic setting for the region between 40º and 42º L.S., further west of 70º L.O. The analyzed rocks are mainly granitoids (some migmatite and metabasite), with clear evidences of ductile deformation. Previously, all these rocks have been isotopically dated by U-Pb, K-Ar and Sm-Nd methods, and then the crystallization and metamorphism ages, and extraction time from the mantle are known. According to their geological ages they have been separated into Gondwanic- (Carboniferous-Permian) and Chanic Groups (Devonian). In both cases, the granitoids are subalkaline, normal calc-alkaline, I- type, peraluminous, and related to their respective volcanic arcs, developed on continental margin. The Gondwanic granitoids were also compared with the granitoids of the same age ranging from Northpatagonian Massif, Cordillera Norpatagónica, and Cordillera Frontal from Mendoza (Argentina) and Chile.